Valves with mechanically attached, e.g., bolted-on, mounting flanges are well known. Mounting flanges can be used to attach a variety of equipment to the valve, such as, for example, a gear or actuator for operating a stem to open and/or close the valve. Some valve bodies are made of relatively expensive materials such as titanium, and it may be desired to employ a mounting flange made of a less expensive material such as steel or stainless steel, e.g., for economic reasons. For example, if the valve is used in high temperature service, the material of the mounting flange may have a thermal expansion coefficient that is different than the material of which the valve is made, resulting in excessive thermal stresses developing in the mounting flange which might lead to premature failure of the valve, mounting flange and/or any mechanical attachment to the valve, e.g., pins, bores, etc. Additional strength can be provided by welding the mounting flange directly to the valve; however, the thermal stresses can likewise lead to failure of the weld, valve, and/or mounting flange.
The present invention can provide a thermally compensated mounting flange that can reduce thermal stresses associated with the use of dissimilar materials in the construction of the mounting flange and/or the equipment to which it is mechanically secured, for example, in high temperature service.